The Primate Animal Model Core (Core 9002) of the Emory University Center for Neuroscience of Mental Disorders (CNMD) will serve as the source of all non-human primates used by the Research Projects. The primary goal of this Core is to produce, maintain and characterize a non-human primate epigenetic early life stress (ELS) model involving neonatal exposure of rhesus monkey (M. mulatta) mother-infant dyads to social instability in the form of intermittent maternal separations. In this protocol, beginning at 3 months postpartum mothers are removed from social groups composed of 4-5 females and a single male for short (0.5, 3 or 6 hr) intervals. Both the timing and the duration of each separation are determined by a pseudo-randomized schedule. Animals experience a total of 36 separations over a 90 day period (from 3-6 months of age). Over the past 4 years, this Core has produced and characterized approximately 70 animals (approx. 20 animals per year beginning in year 02). Extensive neuroendocrine and behavioral characterization along with structural MRI is performed to determine and verify the phenotype of these animals. One important goal of this Core is to characterize developmental changes in these animals as they pass through significant transitions such as puberty. Animals are assigned to individual Conte Projects as required for specific studies of hypothalamic and extra-hypothalamic CRF systems (Project 0001), immune system function (Project 0009), acoustic startle (Project 0006), cognition and drug abuse liability (Project 0010), multimodal imaging of structural and functional neurocircuits (Project 0013). This procedure offers important advantages and sources of validity: (1) the contingencies imposed by the paradigm are naturalistic, infant development is influenced by unpredictable changes in mother's availability, (2) the demands are imposed during a critical period of development when infants solicit reassurance as they begin to explore their environment, (3) as found in some human psychopathologies, deficits are reflected in the capacity of monkeys to respond to stressful experiences as adults. Comparison of this primate model with the genetic and ELS rodent models (see Core 9001) will permit individual Research Projects to test the thesis that, in diverse species, similar neurocircuits and intracellular mechanisms are impacted by genetic and epigenetic factors across which give rise to a depressive-like syndrome. In addition to production, characterization and maintenance of these animals, Core 9003 will assist in sampling or surgical procedures, drug treatments, or necropsy as required by individual Research Projects. This organization allows consistency in animal handling and implementation of all protocols so that each Conte Research Project receives identically characterized and treated animals for study.